Make VEA test support videos with different coded size and visible size

base/files/memory_mapped_file.h

Index: base/files/memory_mapped_file.h
diff --git a/base/files/memory_mapped_file.h b/base/files/memory_mapped_file.h
index 8a7f045f351a0365d496f37f5824607cacfdc12e..d69e665dd63789f2df263c25f687b3b7f3426d0e 100644
--- a/base/files/memory_mapped_file.h
+++ b/base/files/memory_mapped_file.h
@@ -58,13 +58,21 @@ class BASE_EXPORT MemoryMappedFile {
   // As above, but works with a region of an already-opened file.
   bool Initialize(File file, const Region& region);
 
+  // As above, works with an already-opened file and enables write permission
+  // when |write| is true.
+  bool Initialize(File file, bool write);

[rvargas (doing something else), 2014/08/29 20:08:58]

These two methods look like simple supersets of the two previous methods. It
seems better to remove the two previous methods (this is in effect an extra
argument with a default value, which is strongly discouraged).

A second alternative would be to send the write intent to the name of the method
and remove the argument, but still, the first alternative seems better. This
class is becoming a collection of one-off initializers... we are adding support
for writable mappings and yet I can't do that from a FilePath :(

... and we need unit tests.

[henryhsu, 2014/09/01 05:53:44]

If using default value for extra argument is strongly discouraged, why not keep
all Initialize functions?

If we have writable mapping from a FilePath, we should consider the file access
is FILE_OPEN, FILE_CREATE, FILE_CREATE_ALWAYS, or FILE_OPEN_ALWAYS.
So I prefer that let caller decide this.

BTW, Could you tell me how to test windows part?
I added two test cases and passed in posix environment.
Do you have instructions to use virtual machine to run unittest in Windows?

[wuchengli, 2014/09/01 06:57:15]

rvargas means removing Initialize(File) and Initialize(File, const Region&) and
changing the callers to use your functions.

+
+  // As above, but works with a region of an already-opened file and enables
+  // write permission when |write| is true.
+  bool Initialize(File file, const Region& region, bool write);

[wuchengli, 2014/08/29 10:03:11]

I think this can be removed. This can be added in the future when someone
actually uses it.

[henryhsu, 2014/09/01 05:53:45]

I prefer to keep this because every Initialize function can use this.

+
 #if defined(OS_WIN)
   // Opens an existing file and maps it as an image section. Please refer to
   // the Initialize function above for additional information.
   bool InitializeAsImageSection(const FilePath& file_name);
 #endif  // OS_WIN
 
-  const uint8* data() const { return data_; }
+  uint8* data() const { return data_; }
   size_t length() const { return length_; }
 
   // Is file_ a valid file handle that points to an open, memory mapped file?
@@ -85,7 +93,8 @@ class BASE_EXPORT MemoryMappedFile {
 
   // Map the file to memory, set data_ to that memory address. Return true on
   // success, false on any kind of failure. This is a helper for Initialize().
-  bool MapFileRegionToMemory(const Region& region);
+  // - |write| is used to enable write permission of mmap.
+  bool MapFileRegionToMemory(const Region& region, bool write);
 
   // Closes all open handles.
   void CloseHandles();